You can use vmware to help test different resolutions. In your case, I believe it will just be scaled down to fit into your res, but will tell you if everything is where you want it to be. See Here. Came in very handy when tweaking my iCham2 theme for various resolutions.

I've actually thought about making some very simple menu icons, and the other misc icons, that I could just use when I don't feel like making special menu icons =P. Simple ones whose color I can change easily, and I could even upload the PSD for. If I then used them more often, maybe I'd be able to crank more themes out haha.